| 摘要 |
A signal processor converts quadrature phase signals, from an encoder, representative of a measured parameter, into data which is directly readable by a computer and representative of the magnitude and direction of the current value of the parameter. The signal processor decodes binary signals representative of successive samples of the quadrature phase signals into UP signals, DOWN signals, ERROR signals and NO CHANGE signals. The UP and DOWN signals are converted into corresponding pulse streams which drive an up-down counter. Range control circuitry facilitates extension of the measuring range of the processor beyond that of the counter. Error control circuitry provides an ERROR INTERRUPT signal to the computer when an illegal condition occurs and also preserves the last valid data occurring before the illegal condition. Change control circuitry advises the computer when a change in the parameter being measured is initiated and completed so that the computer can selectively sample processor output data only in response to changes in the measured parameter.
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